U.S. District Judge William Griesbach ruled Wednesday the U.S. Environmental Protection Agency and state Department of Natural Resources acted properly in imposing the dredging and capping of the river bottom for remediating environmental damage caused by paper company chemicals known as PCBs.

Regulators filed a federal lawsuit against NCR Corp. and 11 others in 2010. Griesbach wrote there was no evidence of a "nefarious government plot" favoring the more expensive dredging rather than capping alone.

The Milwaukee Journal Sentinel reported the project's cost is estimated at more than $1 billion.

A message left for a spokesman for the remediation company set up for the cleanup wasn't immediately returned Friday.

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